4. Oct. 9-chapter four -mind and consciousness.docx

Chapter 4: The Mind and Consciousness October 9, 2012
Two Points of the Chapter
1. People can be conscious of their surroundings even when they do not appear to be
2. Conscious experiences are associated with brain activity and understanding this brain activity
and understanding this brain activity may help understand consciousness
 Consciousness –subjective experience of the world and of mental activity
o Two components of consciousness
1. Level of consciousness  ie. coma, sleep, wakefulness
2. Contents of consciousness  what things we are conscious of
CONSCIOUSNESS IS A SUBJECTIVE EXPERIENCE
 We cannot know if any two people in the world experience it in exactly the same way
 Qualia –the term to describe the properties of our subjective experiences (perception)
 Persistent Vegetative State –when a person in a coma has sleep/wake cycles (open eyes and
appear to be aware, close eyes and appear to be asleep) that last over a one month period of
longer
 Minimally Conscious State –in which a person in a coma make some deliberate movements and
may TRY to communicate
SPLITTING THE BRAIN, SPLITS THE CONSCIOUS MIND
 General theme: complexity of consciousness
o IE. Levels of consciousness, paradox of specialized brain areas as well as integration,
 Split Brain –a condition in which the corpus callosum is surgically cut and the two hemisphere of
the brain do not receive information directly from each other
 Images from the visual field’s left side go to the right hemisphere; and those from the right side
go to the left hemisphere (input)
 Left hemisphere: better with language, analytic thought, math and science, logic, identifies faces
 Right hemisphere: better with spatial relationships, design, intuition, creativity, art and music,
identifies fruits instead of faces
 Also, the left hemisphere controls the right hand and vice versa (output)
 Interpreter –a left hemisphere process that attempts to make sense of events; creating
coherence
o Propensity to construct a world that makes sense
o Influences the way we view and remember the world
 When you split the brain, do you split the mind?
o The corpus callosum connects the brain’s hemispheres
o Severing the corpus callosum produces split brain
 Jill Bolte Taylor –Stroke of Insight (Ted Talks) THE UNCONSCIOUS PROCESSING INFLUENCES BEHAVIOUR
 Subliminal Perception –information processed without conscious awareness
o Don’t reach consciousness due to their short durations or subtle forms
BRAIN ACTIVITY PRODUCES CONSCIOUSNESS
 Blindside –a condition in which people who are blind have some spared visual capacities in the
absence of any visual awareness
 Global Workspace Model –poses that consciousness arises as a function of which brain circuits
are active
o You experience your brain regions output as conscious awareness
AREAS OF AWARENESS
 Prefrontal cortex  “I understand plans.”
 Frontal Motor Cortex  “I’m all about movement.”
 Parietal Lobe  “I’m aware of space.”
 Temporal Lobe  “I see and hear things.”
 Occipital Lobe  “I see things.”
SLEEP IS AN ALTERED STATE OF CONSCIOUSNESS
 The stages of sleep:
 1. As you drift to sleep, characterized by theta waves –from which you can be aroused
easily. May see shapes or have the falling sensation
 2. Breathing is more regular and you become less sensitive to external stimulation;
continues theta waves with occasional bursts of activity (sleep spindles) and large waves
(k-complexes)
 3/4. Large regular brain patterns called delta waves referred to as slow wave sleep
 Hard to wake except for impending danger (parents hear child’s cry)
 REM Sleep –(rapid eye movement) the stage of sleep marked by rapid eye movements,
dreaming and paralysis of motor systems
 Called PARADOXICAL SLEEP because of the paradox of a sleeping body with an active
brain
 Some neurons in the brain are more active in REM sleep than in the waking hours
SLEEP DISORDERS
 Insomnia –people’s mental health is affected by their inability to sleep
 Pseudo Insomnia –people dream there are not sleeping
 Cognitive Behaviour Therapy (CBT) –treatment for insomnia which helps people overcome their
worries about sleep
 Sleep Apnea –a disorder in which a person stops breathing for short periods while asleep,
resulting in loss of oxygen and sleep disruption
 Narcolepsy –a disorder in which people fall asleep during normal waking hours
o May experience the muscle paralysis associated with REM sleep o Treated as an auto immune disorder
 REM behaviour disorder –roughly the opposite of narcolepsy dreams
o The paralysis of REM is disabled so they act out dreams while sleeping
o Rare; caused by neurological deficit; usually seen in elderly males
 Somnambulism –sleep walking
SLEEP IS AN ADAPTIVE BEHAVIOUR

 Three explanations for sleep’s adaptiveness:
 Restorative Theory –sleep allows the brain and body to rest and repair themselves
o Sleep deprivation can lead to attention lapses, reduced short term memory and
compromised immunity
o Micro sleeps –brief, unintended sleep episodes, ranging from a few seconds to a
minute caused by chronic sleep deprivation
o Also called “Restoration and Sleep Deprivation”
o Sleep deprivation can help cure depression as the brain produces higher levels of
serotonin
 Circadian Rhythms –the regulation of biological cycles into regular patterns
o Protects.
o Humans depend greatly on vision and have adapted to sleeping at night because the
lack of light increases danger
 Facilitation of